We batch concrete when you need it. Concrete is a mixture of sand, gravel, cement, and water. Generally the more sacks of cement per yard of concrete the stronger the concrete will be. We can make concrete with 3/4 inch rock or 3/8 inch rock. The larger the rock the stronger the concrete. Water also effects the strength of the concrete. Drier, low slump concrete is stronger, but harder to finish. As a general rule a 5 sack mix, with 3/4 inch rock, and a 4 inch slump will give a 2500 PSI rating. This is strong enough for residential driveways and sidewalks.